Development of a yeast cell factory for production of aromatic products

There is much interest in aromatic chemicals in the chemical industry as these can be used for production of dyes, anti-oxidants, nutraceuticals and food ingredients. Yeast is a widely used cell factory and it is particularly well suited for production of aromatic chemicals via complex biosynthetic routes involving P450 enzymes. In Saccharomyces cerevisiae the fluxes towards aromatic acids (L-tryptophan, L-tyrosine and L-phenylalanine) are strictly controlled on transcriptional and kinetic levels and therefore are difficult to manipulate.
We engineered S. cerevisiae for increased production of aromatic compounds by eliminating degradation, up-regulating the key enzyme encoding genes, and removing feed-back inhibition in the pathway. In order to test the strain performance we overexpressed heterologous pathway for coumaric acid production. We obtained 4-fold higher concentrations of coumaric acid in the engineered strain compared with the reference strain. Overexpression of the enzymes prephenate dehydrogenase and transketolase had a negative effect on production of coumaric acid. In summary, we developed a S. cerevisiae platform strain suitable for production of aromatic amino acids-derived compounds.